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July 11, 2013

ESRI UC: Geodesign projects in 3D

At the ESRI User Conference Eric Wittner, a 3D Technology Evangelist, at ESRI presented some Geodesign projects that involve 3D that ESRI has worked on. This was very interesting because it provides a practical perspective on what ESRI considers geodesign to be and secondly how existing software tools can be used for Geodesign.

Geodesign

Based on my experience at the Geodesign Summit last January i've blogged about the different views of what geodesign is, so I won't reiterate that here. Eric's perspective is practical. Geodesign is design that considers geography.

Geodesigning really isn't new. People have been making this type of design decisions since we have been had buildings and towns. Many cities are near water bodies for obvious reasons. Some cities are not near water for other reasons, for example, to avoid mosquitoes and malaria. Eric provided a classic example of bad and good geosdesign in the U.S. by comparing a standard American suburban development with Frank Lloyd Wright's renowned waterfall house.

Architecture and GIS

He mentioned the early geodesign pioneer Ian McHarg who developed geodesign techniques before the term was invented. McHarg’s book Design with Nature, published in 1969, pioneered ecological planning. Geographic overlay maps were not invented by Ian McHarg, founder of the Department of Landscape Architecture at the Universityof Pennsylvania, but were popularized by him within the architectural profession. Some of the tools used by McHarg that would be familiar to GIS people include overlay maps, transects, diagrams, drawings, bird’s eye perspective, photography and block diagrams. But McHarg did all this with paper, mylar and acetates because he didn't have the computerized GIS tools we have today.

Modern geodesign is a systematic approach to design that uses computer GIS tools to incorporate geography into the process of designing(planning) buildings and infrastructure. Initially geodesign used 2D tools exclusively. But now as 3D is being integrated into GIS tools, geodesign is also beginning to leverage 3D and some of the examples that Wittner showed used 3D.

Geodesign as a process

From the examples I have seen, the focus of geodesign, at least in how it is used at the present, is on the planning phase, rather than the design phase of the construction lifecycle. But like BIM processes, geodesign is collaborative, but it is perhaps more multi-disciplinary (involving a wider range of stakeholders including politicians and the public), multi-scale (involving different levels of government) and iterative (typical in planning) than is typical of most BIM design processes.

As a simple infrastucture example, if you have ever been to Redlands you'll know that it is not a pedestrian-friendly place. Roads are wide, cars go fast, often there are not sidewalks, or sidewallks disappear into rail lines. On a hot day, you're likely exposed to direct sun. Wittner gave a very simple example of how geodesign could be used to encourage people to walk or bicycle in Redlands by narrowing roads, adding sidewalks, and planting trees to provide shade. But the key to success in making simething like this happen is that you have to get all the stakeholders participating in the planning process.

City of Honolulu

Another example is the City
of Honolulu where the challenge was to accomodate 140,000 new residents
without significatly increasing Honolulu's infamous traffic problem and
suburban sprawl. They knew they had to grow up rather than out.

What
was being proposed was a light rail system. They looked at each
station, did a 2D walkability analysis to identify areas where Americans
would be willing to walk. They found that they could acoomodate 80% of
the 140,000 new residents in areas that were within walking distamce of
light rail stations.

They then created a 3D basemap,
by using a rule-based procedure to create fairly realistic (textured)
models of existing buildings. Then based on zoning, they created 3D
models of potential buildings to show what the maximum development would
look like based on zoning restrictions. But the City wanted realistic
representations of buildings, so the project team automatically textured the
buildings based on building type. They found that with a rule-based
approach it was fairly easy to accomodate changes made by the
contractors and the City.

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The City then wanted to show what the alternative development would look like if they didn't densify, and allowed more sprawl and worse traffic. From this analysis they found that by densifying they preserve 105 000 acres from development.

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In
this example, 3D was used primaily to be able to visualize for city
leaders and the public what the proposed development would look like. This is fairly typical of the use of 3D for this type of project.

Philadelphia Logan Square

Wittner described a very interesting geodesign project In Philadelphia where the objective was to rezone a part of Philadelphia to encourage economic development. For this project 3D was esentail to the analysis.

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Again, this involved an interative process. They first assessed the existing buildings and spaces, created 3D models of the existing buildings, and then did a multi-criterion suitability map to assess development potential. Their first attempt showed very little potential for development, primarily because of limited accessability.

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They then extended a light rail system into the area and found that it enabled much more development potential. They then created 3D models of potential new buildings and looked at times to walk to the light rail stations from different floors, opportunities for residential, commercial, and retail development at different locations and on different floors with different zoning policies, for example, zoning for higher buildings.

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For residential potential they used criteria like proximity to retail and light rail, parking, and quality of view. For quality of view, they identified historic buildings, waterfront, and other features that would contribute to what people would like to see. Because they could calculate the square footage available on different floors and at different locations, they had a metric for assessing the development potential for residential, commercial, and retail under different zoning policies. For example, higher buildings tend to favor more residential because the quality of view is better on higher floors.

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This is an example where 3D is essential part of the analytics of the project.